| Auxin | - Cell elongation | - Synthesized primarily in apical meristems | Polar transport | - Binding to receptor proteins in cells | - Rooting hormones, herbicides, and plant growth regulators |
| - Apical dominance | and young leaves | (basipetal and | - Activation of AUX/IAA genes | |
| - Root development | - Derived from tryptophan amino acid | acropetal) | - pH changes in cell walls | |
| - Tropisms (e.g., phototropism, gravitropism) | | | | |
| Gibberellin | - Stem elongation | - Synthesized in shoot tips and young leaves | Non-polar transport | - Binding to specific receptors in cells | - Promoting stem elongation, improving yields |
| - Seed germination | - Complex enzymatic pathway | (both acropetal and | - Activation of gene expression | |
| - Flowering regulation | | basipetal transport) | - DELLA protein degradation | |
| - Fruit development | | | | |
| Abscisic Acid | - Stress response | - Synthesized in various plant tissues | Diffusion and | - Binding to specific receptors in cells | - Enhancing stress tolerance, seed dormancy |
| - Stomatal regulation | - Derived from carotenoids | vascular transport | - Activation of stress response genes | |
| - Leaf abscission | | | - Regulation of stomatal closure | |
| - Seed dormancy | | | - Promotion of leaf senescence | |
| Ethylene | - Fruit ripening | - Synthesized mainly from methionine | Gas (diffusion) | - Binding to specific receptors in cells | - Ripening of fruits, promoting senescence |
| - Senescence | - Enzymatic reactions | | - Activation of transcription factors | |
| - Leaf abscission | | | | |
| - Stress response | | | | |
| Cytokinin | - Cell division and growth | - Synthesized in roots, young leaves, seeds | Xylem and phloem | - Binding to specific receptors in cells | - Promoting cell division, shoot and root development |
| - Shoot development | - Conversion of AMP to various cytokinins | | - Activation of cell division-related genes | - Used in plant tissue culture, improving crop yield |
| - Root development | | | | |
| - Nutrient uptake | | | | |
| - Delay in senescence | | | | |
BETA
